Blackfoot River, Southeastern Idaho

Sceintists from the U.S. Geological Survey and the Idaho Department of Environmental Quality combined and analyzed data from two separate water-quality monitoring efforts in the upper Blackfoot River of southeastern Idaho. The river receives runoff from 12 phosphate mining opoerations, and waste rock material from mining is highly enriched in naturally occuring selenium. Elevated concentrations of selenium in the river have raised concern about possible impacts to aquatic life and grazing livestock.